FIG. 2.

Vaccinated perforin-KO mice control virus challenge. Perforin-KO and wild type (B6) mice were vaccinated with DNA (D) and vaccinia virus (V) in a prime-boost regimen. Inoculations were in the order D-D-V. One month after the last injection, vaccinated and unvaccinated mice were challenged with rSeV-env (1 × 10⁵ PFU/animal, intranasal administration). Mice were administered ip injections with the anti-CD8 2.43.1 mAb on days −5, −3, −1, +1, and +3 relative to rSeV-env challenge. On day 5 after challenge, groups of vaccinated challenge and groups of vaccinated and unvaccinated mice were sacrificed. Lungs were harvested and the titers of challenge virus in the lungs were determined by a TCID50 measurement on LLC- MK2 cells. The Reed–Muench formula was used to calculate the TCID50. Each symbol represents the TCID50 of a different animal. The levels of protection demonstrated in the vaccinated mice of both perforin-KO and wild type strains were statistically significant (p < 0.05).